PRISONER'S DILEMMA

The prisoner's dilemma is a two player game in which the object is to gain more points by inducing your opponent to cooperate with you. The table below shows the payoffs for the two players, given the choice of cooperating or defecting for each player. If both cooperate, each gets 3 points. If both defect, each gets 1 point. The highest payoff, 5, comes if your opponent cooperates and you defect. In this case your opponent gets the "sucker's payoff" of 0. The number of turns in the game is not known to the players, although you do know that at some point the game will be stopped.

Think about playing the game. Can you devise a strategy (a combination of cooperation and defection) which will induce your opponent to cooperate? After you've thought about it a while, check these strategies.

What is your best strategy if you know the next turn is the last turn of the game?

Try the game a few times, and see which strategy (you can try your own of one from the list at strategies) gives you the best result. To see how various strategies fare in computer simulations, click here.

Game theory references:

Axelrod, Robert 1985 The Evolution of Cooperation Basic Books

Davis, Morton D. 1997 Game Theory : A Nontechnical Introduction Dover Pubns.

Dugatkin, Lee Alan and Hudson Kern Reeve, eds. 2000 Game Theory and Animal Behavior Oxford Univ Press

Lomborg, Bjorn 1996 The Structure of Solutions in the Iterated Prisoner's Dilemma (Center for International Relations Series) Univ of California LA